Biochemical tests Flashcards
1
Q
What is the test for reducing sugars?
A
- Add benedict’s solution to the test tube with food sample
- Heat in water bath at 80C for 5 minutes
- Colour change from blue to brink red
2
Q
What is the test for starch?
A
- Add iodine dissolved in potassium iodide solution to test tube with food sample
- Colour change from orange to blue/black
3
Q
What is the test for lipids?
A
Emulsion test:
- Add ethanol to food sample and shake
- Add water to solution and shake
- Milky white emulsion appears
4
Q
What is the test for protein?
A
- Add biuret solution
- Colour change from blue to purple
5
Q
What is the test for non-reducing sugars?
A
- Add dilute hydrochloric acid
- Heat in water bath at 80C for 5 minutes
- Cool and add sodium hydrogencarbonate (to neutralise)
- Add benedict’s solution
- Put in water bath for another 5 minutes
- Colour change blue to brick red
